JSON file is parsed and used if it exists

From now on, the JSON file is parsed and used if it exists.

Improve relay list parsing to handle 'wss://' prefixes.

Your question on the last PR was:

won't this break all the .envs and the existing examples because they don't have wss?

As in the getRelayList method, a wss:// is also placed in front.

The same is done in the getRelayListFromFile. The JSON can contain a list with or without wss:// as a prefix.

bitvora / haven